Intertemporal Insurance

This paper develops a discrete-time general equilibrium model of insurance using standard techniques of intertemporal finance. The underlying source of uncertainty is modeled as a marked point process. The paper begins by characterizing Walrasian equilibrium on the event tree generated by the accident process. The corresponding Arrow-Debreu-Radner contingent-commodity prices allow the pricing of insurance contracts. A transformation of the underlying probability measure gives an alternative characterization of insurance contract prices plus accumulated payouts as martingales. A direct application of the usual dynamic spanning argument demonstrates that one insurance contract for each type of accident suffices, at least generically, to achieve market completeness. The theory is illustrated by a simple example in which consumers have Cobb-Douglas preferences and experience accidents at a rate which varies across individuals but remains constant over time, the traditional setting for much of insurance theory. This paper was presented at the Financial Institutions Center's May 1996 conference on "

Where is the value in high frequency trading?

Analizamos el impacto de las operaciones que se realizan en mercados financieros a gran velocidad utilizando un modelo con tres tipos de operadores: consumidores de liquidez, creadores de mercado y operadores de alta frecuencia. Nuestros cuatro resultados principales son: i) el impacto de las operaciones de liquidez sobre los precios es mayor cuando hay operadores de alta velocidad y este efecto adicional aumenta con el tamaño de la operacion. En concreto, demostramos que la presencia de operadores de alta frecuencia reducen (aumentan) los precios que los consumidores de liquidez reciben cuando venden (adquieren) sus participaciones en Bolsa. ii) Aunque los creadores de mercado tambien pierden ingresos en sus operaciones con operadores de alta frecuencia, estas perdidas se ven compensadas por un mayor descuento de liquidez. iii) Las operaciones a gran velocidad aumentan la volatilidad en los precios. iv) El volumen de negocio se dobla ya que el operador de alta frecuencia intermedia en todas las transacciones entre consumidores de liquidez y creadores de mercad

Marketinaren erabilera moda sektorean: Adolfo Domínguez-en kasua

Lan honetan modaren marketina zer den eta nola erabiltzen den azaltzen saiatu gara. Argi dago hazkunde handieneko eta lehiakorreneko sektorea izan dela azken urteotan, eta etorkizunean indartzen eta hazten jarraituko duen sektorea izango da. Sektore honetako aldaketak, neurri handi batean, merkatua partekatzen duten kontsumitzaileen lehentasunen araberakoak dira. Horretarako, Adolfo Domínguez enpresa espainiarra aztertuko da, marketinari buruzko teoriak eta ezagutzak une oro aplikatuz, eta, beraz, enpresaren marketin estrategikoa nahiz operatiboa analizatuz

Vitamin C content of rotifers enriched with the microalga Isochrysis AFF. galbana (T-ISO) collected from different growth conditions.

The aim of our study was to evaluate if different vitamin C contents in T-iso from different growth phases and conditions would lead to correspondingly different vitamin C contents in rotifers enriched with these microalgae.We conclude that the vitamin C content of rotifers can be manipulated by enrichment with cultures of T-iso with different vitamin C content, obtained by different growth conditions. However, special care should be taken to ensure that DW:rotifer ratios in the enrichments do not vary much or are above the ratio when maximum ingestion rates are reached. Acknowledgments: This work was supported by project P08-AGR-3695, Junta de Andaluc&iacute;a, Spain and by Interreg Project ECOAQUA, financed by the EDRF (European Regional Development Fund). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua.El objetivo de nuestro estudio fue evaluar si los diferentes contenidos de vitamina C en T-iso de diferentes fases y condiciones de crecimiento llevar&iacute;a a diferentes contenidos de vitamina C en los rot&iacute;feros enriquecidos con estas microalgas Nosotros concluimos que el contenido de vitamina C de rot&iacute;feros puede ser manipulado mediante el enriquecimiento con cultivos de T-iso con diferente contenido en vitamina C, obtenidos por diferentes condiciones de crecimiento. Sin embargo, se debe tener especial cuidado para asegurar que en peso seco, las relaciones de rot&iacute;feros en los enriquecimientos no var&iacute;an mucho y est&aacute;n por encima de la tasa cuando se alcanzan los niveles m&aacute;ximos de ingesti&oacute;n. Agradecimientos: Este trabajo fue apoyado por el proyecto P08-AGR-3695, Junta de Andaluc&iacute;a, Espa&ntilde;a y por Interreg EcoAqua proyecto, financiado por el FEDER (Fondo Europeo de Desarrollo Regional). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua.</p

Destructive effects of murine arthritogenic antibodies to type II collagen on cartilage explants in vitro

Certain monoclonal antibodies (mAbs) to type II collagen (CII) induce arthritis in vivo after passive transfer and have adverse effects on chondrocyte cultures and inhibit self assembly of collagen fibrils in vitro. We have examined whether such mAbs have detrimental effects on pre-existing cartilage. Bovine cartilage explants were cultured over 21 days in the presence of two arthritogenic mAbs to CII (CIIC1 or M2139), a non-arthritogenic mAb to CII (CIIF4) or a control mAb (GAD6). Penetration of cartilage by mAb was determined by immunofluorescence on frozen sections and correlated with changes to the extracellular matrix and chondrocytes by morphometric analysis of sections stained with toluidine blue. The effects of mAbs on matrix components were examined by Fourier transform infrared microspectroscopy (FTIRM). A possible role of Fc-binding was investigated using F(ab)(2 )from CIIC1. All three mAbs to CII penetrated the cartilage explants and CIIC1 and M2139, but not CIIF4, had adverse effects that included proteoglycan loss correlating with mAb penetration, the later development in cultures of an abnormal superficial cellular layer, and an increased proportion of empty chondrons. FTIRM showed depletion and denaturation of CII at the explant surface in the presence of CIIC1 or M2139, which paralleled proteoglycan loss. The effects of F(ab)(2 )were greater than those of intact CIIC1. Our results indicate that mAbs to CII can adversely affect preformed cartilage, and that the specific epitope on CII recognised by the mAb determines both arthritogenicity in vivo and adverse effects in vitro. We conclude that antibodies to CII can have pathogenic effects that are independent of inflammatory mediators or Fc-binding

Pigment patterns in adult fish result from superimposition of two largely independent pigmentation mechanisms

5 figuras, 14 páginasDorso-ventral pigment pattern differences are the most widespread pigmentary adaptations in vertebrates. In mammals, this pattern is controlled by regulating melanin chemistry in melanocytes using a protein, agouti-signalling peptide (ASIP). In fish, studies of pigment patterning have focused on stripe formation, identifying a core striping mechanism dependent upon interactions between different pigment cell types. In contrast, mechanisms driving the dorso-ventral countershading pattern have been overlooked. Here, we demonstrate that, in fact, zebrafish utilize two distinct adult pigment patterning mechanisms – an ancient dorso-ventral patterning mechanism, and a more recent striping mechanism based on cell–cell interactions; remarkably, the dorso-ventral patterning mechanism also utilizes ASIP. These two mechanisms function largely independently, with resultant patterns superimposed to give the full patternThis work was funded by the Spanish Science and Innovation Ministry project ALG2011-23581 and Xunta de Galicia INCITE-09 402 193 to JR. Partial funding was also obtained from Science and Innovation Ministry (AGL2013-46448-C3-3-R to JMC-R). R.M. Ceinos was supported by post-doctoral fellowship JAE-Doc (IIM-CSIC) cofunded by the European Social Fund, with additional support from two mobility grants: Jos e Castillejo fellowship from the Spanish Ministry of Education and EuFishBioMed from the European COST Action code EUFishBioMed (BM0804). The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.Peer reviewe

Árboles viejos como indicadores de biodiversidad de vertebrados forestales amenazados de la provincia de Salamanca (España)

Ancient trees abundance has been compared with distribution of threatened forest vertebrate species at the province of Salamanca (Spain). A significant correlation between both parameters has been observed for the following considered species: imperial eagle (<em>Aquila adalberti</em>), black vulture (<em>Aegypus monachus</em>), iberian lynx (<em>Lynx pardinus</em>), red kite (<em>Milvus milvus</em>) and a group of forest bats (<em>Miniopterus schreibersii, Myotis bechsteinii, Myotis emarginatus, Myotis mystacinus, Myotis myotis, Nyctalus lasiopterus, Nyctalus noctula, Rhinolophus euryale, Rhinolophus ferrumequinum</em> y <em>Rhinolophus mehelyi</em>). It has been proved that there is an increase of threatened forest vertebrates biodiversity along with increasing ancient trees density at the municipalities of the province. Therefore, we can deduce that ancient trees density is a good indicator parameter of the conservation status of the forest ecosystem and it is essential for the maintenance of these endangered species.<br><br>Se ha comparado la abundancia de árboles viejos en la provincia de Salamanca (España) con la distribución de las especies de vertebrados forestales amenazados presentes, observándose que existe una correlación significativa entre ambos parámetros para las siguientes especies estudiadas: águila imperial (<em>Aquila adalberti</em>), buitre negro (<em>Aegypus monachus</em>), lince ibérico (<em>Lynx pardinus</em>), milano real (<em>Milvus milvus</em>) y un grupo de especies de quirópteros forestales (<em>Miniopterus schreibersii, Myotis bechsteinii, Myotis emarginatus, Myotis mystacinus, Myotis myotis, Nyctalus lasiopterus, Nyctalus noctula, Rhinolophus euryale, Rhinolophus ferrumequinum</em> y <em>Rhinolophus mehelyi</em>). Se ha demostrado que existe un incremento de la biodiversidad de vertebrados forestales amenazados paralelo al aumento de la densidad de árboles viejos en los municipios de la provincia. Por ello, se puede deducir que la densidad de árboles viejos es un buen parámetro indicador del estado de conservación del ecosistema forestal y clave para el mantenimiento de dichas especies amenazadas